All but one of the 48 Republican hopefuls for the Senate mid-term elections in November deny the existence of climate change or oppose action on global warming, according to a report released today.

The strong Republican front against established science includes entrenched Senate leaders as well as the new wave of radical conservatives endorsed by the Tea Party activists, says a report by the Centre for American Progress.

As election season gets under way, Tea Party favourites such as Joe Miller, who caused the biggest upset of the primaries when he defeated the Republican incumbent Lisa Murkowski in Alaska last month, have been upfront about their doubts on climate science. "We haven't heard there's manmade global warming," Miller told the Fairbanks Daily News-Miner.

But the challenge to science goes beyond Tea Party favourites to corporate titans such as Carly Fiorina, who was the chief executive of Hewlett-Packard, and is running for the Senate in California. Fiorina has said on repeated occasions that she is "not sure" climate change is real.

Even John McCain, the two-time presidential candidate who worked for years to get climate change legislation through the Senate, has now cooled on the idea, calling a recent cap-and-trade bill a "monstrosity". Only one Republican contender, Mike Castle of Delaware, has bucked the Republican line against climate science. But he faces a tough battle in the primary election from emerging favourite Christine O'Donnell, who has said climate action would kill jobs. The rising opposition to science and action on climate change caps a year of crushing defeats for environmentalists in Congress. Supporters of action on climate change now fear that Congress could be weighted even more against them, once the elections are over. "If they win, the number of card-carrying members of this "Flat Earth Society" will rise exponentially in the world's greatest deliberative body," said Gene Karpinski, the president of the League of Conservation Voters, in an email to reporters.

Lobbyists for the oil and gas industry have acknowledged they see the November elections as crucial to their interests.

In a conference call with reporters, Jack Gerard, president of the American Petroleum Institute, said the oil and gas lobbying organisation would take a leading role in the elections. "We will be involved in the elections," he said. "We will continue our advertising efforts. We will continue to refine our message."

As the Climate Progress report points out, many of the Senate candidates have formally signed on to rightwing movements such as Americans for Prosperity and Contract from America, which explicitly reject putting a price on carbon.